Method of installing insert ring in pipe unions

ABSTRACT

A pipe union or the like including a body portion having a sealing ring insert positioned in a recess provided by the body and a method of forming and installing the ring insert are disclosed. According to the method, the sealing ring is formed to provide a work-hardened sealing and interlocking portion which extends about the entire periphery of the ring. The sealing ring is forged into the recess, embedding and sealing the interlocking portion in the side wall of the recess and intimately contacting the adjacent ring and recess walls to provide a fluid-tight seal and mechanically interlock the ring within the recess.

United States Patent Fink 1 51 Aug. 22, 1972 METHOD OF INSTALLING INSERT1,905,115 4/ 1933 Lofgren ..277/172 RING IN PIPE UNIONS 3,1 16,06712/1963 Kinzie et a1 ..277/170 [72] Inventor, Frank Fink, Chardon Ohio3,150,889 9/1964 Watts ..277/170 X [73] Assignee: The ImperialManufacturing and FOREIGN PATENTS OR APPLICATIONS g g p y fi l 1,185,8761/1965 Germany ..277/236 10 22 Fl (1: M 11 197 Primary ExaminerCharlieT. Moon 1 1 e ay 0 Attorney-McNenny, Farrington, Pearne and Gordon [21]Appl. No.: 36,278

[57] v ABSTRACT [52] US. Cl. ..29/417, 29/432, 29/509, A pipe union orthe like including a body portion hav- 29/523, 29/ 1 56.7 A, 285/3341ing a sealing ring insert positioned in a recess provided [51] Int. Cl...B23p 17/00 by the body and a method of forming and installing [58] Fild f S a h 277/170 172; 29/523, 509 the ring insert are disclosed.According to the method, 29/522 432 15 7 A, 4 7; 235 3322 3341 thesealing ring is formed to'provide a work-hardened sealing andinterlocking portion which extends about 5 References Cited the entireperiphery of the ring. The sealing ring is forged into the recess,embedding and sealing the in- UNITED STATES PATENTS terlocking portionin the side wall of the recess and intimately contacting the adjacentring and recess walls 1,959,068 5/1934 Stoll. ..29/156.7 A to provide afluid tight Seal and mechanically interlock 2,017,154 10/1935 Larkm..29/156.7 A UX the ring within the recess I 2,332,355 10/1943 Stecher..285/334.1 X 1,523,817 1/1925 Long ..277/170 4 Claims, 5 DrawingFigures METHOD OF INSTALLING INSERT RING IN PIPE UNIONS FIELD OF THEINVENTION This invention relates generally to pipe unions or the likehaving sealing ring inserts and a method of forming and installing suchring inserts. More particularly, a novel and improved sealing ringinsert is disclosed having a work-hardened portion which tends to embedin the body of the pipe union when the ring is forged into the pipeunion according to the method of the present invention.

Although the present invention relates generally to pipe unions orsimilar pipe connecting fixtures having zone of high interfacial contactpressure which prevents leakage. Such work-hardened portion also tendsto embed in the adjacent sidewall of the recess as the ring is forgedinto intimate contact with the ad- 5 jacent walls of the recess tomechanically interlock the sealing ring inserts, and should nototherwise be limited, it will be discussed hereinafterwith particularreference to pipe unions.

PRIORART Sealing rings for pipe unions as disclosed by the prior art aretypically formed of a substantially non-corrosive, softer material thanthe material used to form the pipe union body. For example, the pipeunion body is usually formed of a ferrous metal and the sealing ring isformed of a softer metal, such as brass. Such sealing rings aregenerally formed by machining or casting operations. In some instances,such rings are formed to fit the recess with an interference fit. Inother instances, cast rings are shaped to fit with clearance into anannular recess provided by the pipe union body. Such cast rings areforged or pressed into the recess, intimately contacting the adjacentwalls of the ring and the recess, to provide a fluid-tight sealtherebetween.

The only patent of which I am aware relating to the forging of sealingrings in such unions is the US. Pat. No. to Lofgren No. 1,905 ,1 15.

The prior art pipe unions having sealing rings as generally describedabove are not entirely satisfactory for a number of reasons. Initially,it may be noted that sealing rings prepared by a machining process arerelatively expensive to manufacture.

Although sealing rings produced by a casting operation are somewhat lessexpensive than machined rings, the cast rings have other disadvantages.For example, the casting operation results in a casting gate projectingfrom one end wall of the ring structure which is not uniform in size andwhich can produce problems in automated feeding and pressing operations.Also, unless the ring is machined to smooth its outer surface beforebeing pressed in place, roughness can produce a leakage path unless veryhigh forging pressures are used. v

In addition, once the cast sealing ring has been properly forged orpressed into the recess, the exposed ring surface must be machined toprovide a good surface finish. I

SUMMARY OF THE INVENTION The present invention provides a pipe unionhaving a body formed of a relatively hard metal and a sealing ringinsert forged within a recess provided by the harder body. The sealingring insert includes a workhardened sealing and interlocking portionextending about the entire periphery of the ring which provides a parts.

According to the preferred method of the present invention, a sealingring is formed without scrap by sequentially cutting rings from the endof a tubular member with a cutting wheel so as to progressively cut thetubular member inwardly from its exterior surface. Therefore, thesealing ring is simultaneously cut to shape and axially deformed toprovide a workhardened portion extending around its periphery. The ringsare then positioned with clearance in a recess in the body and areupsetby axial pressure. This causes the work-hardened portions to pressredially into the body to form a mechanical interlock and a continuouszone of high pressure which provides a positive seal. After the ring hasbeen forged into the recess, the interlocking portion tends to have agreater radius than the adjacent portions-of the body, and therefore thering is compressively stressed by the body with a greater pres-' sure ofengagement, since the body provides greater spring-back than the sealingring. Thus, the sealing ring of the present invention provides asuperior fluidtight seal and mounting, as compared to prior art sealingrings. 7 1

In contrast to the prior art techniques of forming sealing rings, themethod of the present invention is relatively inexpensive and easilyperformed. Specifically, the expensive machining procedures areeliminated, and there are no irregular casting gates which must besubsequently removed.

In addition, a sealing ring manufactured according to the method of thisinvention lends itself to automatic feeding operations, since it issymmetrically formed. In particular, after the first cut, each ring isformed with a radially extending portion positioned adjacent to each ofthe end walls of the ring. Therefore, the ring is inserted into therecess of the body with either of its end walls exposed or adjacent tothe forging tool.

These advantages and others will appear in the following description anddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a pipeunion incorporating a sealing ring according to the present invention;

FIG. 2 is a side elevation illustrating a preferred apparatus forforming a sealing ring according to the method of the present invention;

FIG. 3 is a sectional view of a pipe union and sealing ring before thesealing ring is forged into place;

FIG. 4 is a fragmentary, sectional view on an enlarged scale of the pipeunion and sealing ring shown in FIG. 3, and a forging tool at anintermediate point in the forging stroke, with parts broken away forclarity; and

FIG. 5 is a fragmentary, sectional view similar to Fig. 4, illustratingthe forging tool at the end of the forging stroke.

DETAILED DESCRIPTION OF THE DRAWINGS Referring to FIG. 1, there isillustrated a pipe union 10 having a body portion 12. The body portion12 is usually formed of a relatively hard, ferrous metal casting. Thebody 12 includes an enlarged diameter head portion 14 having externalthreads 16 about its periphery. The body 12 is also provided with anaxially extending bore 18. The bore 18 extends to an annular end face 20adjacent the lower end of .the body 12, as shown in FIG. 1, and it isprovided with internal threads 22 extending from the end face 20.

As shown in FIG. 1, the body 12 is provided with a recess 24 adjacentthe upper end of the bore 18. The recess 24 includes a radiallyextending end wall 26 and a cylindrical sidewall 28. The recess 24extends to an annular end face 30 adjacent the upper end of the body 12,as shown in FIG. l.

A sealing ring insert 32 is positioned within the annular recess 24. Thesealing ring 32 has an axially extending bore 34 having a diameter.substantially equal to the diameter of the bore 18. The sealing ringincludes an end wall 36 and a sidewall 38 which are intimately contactedwith the end wall 26 and the sidewall 28, respectively, of the recess 24so as to form a fluid-tight seal.

- The sealing ring 32 is compressively stressed radially by the body 12and portions of the sidewall 38 are embedded in the recess sidewall 28as described in detail below.

The exposed end face 40 of the ring 32 is substantially coplanar withthe end face 30 of the body 12. A flared sealing surface 42 is providedabout the bore 34 adjacent the end face 40 of the sealing ring.

Referring to FIG. 2, there is illustrated a preferred apparatus forforming sealing rings according to the method of the present invention.As there shown, a tubular member 44 having a suitable bore or innerdiameter 45 and outer diameter 46 is retained and rotated, in thedirection shown by the arrow A, by a chuck 47. A portion of a cuttingtool 48 is shown positioned adjacent one end of the tubular member 44.

The cutting tool 48 includes a central axle 50 and a circular cuttingwheel 52 mounted thereon which rotates in the direction indicated by thearrow B. The cutting wheel 52 is provided with a conical cutting edge 54adjacent its outer periphery.

The cutting tool 48 is supported by any suitable structure (not shown)for radial movement in the direction of the arrow C towards the tubularmember 44. Therefore, as the tubular member 44 and the cutting wheel 52are counter-rotated, the cutting tool 48 is progressively advanced tosever the tubular member uniformly from its outside diameter 46 inwardlyto its inner diameter or bore 45.

As illustrated in FIG. 2, a sealing ring 56 is partially severed fromthe left end of the tubular member 44. As the cutting tool 48 isprogressively advanced towards the rotating tubular member, the conicalcutting edge 54 cuts into the tubular member and axially deforms thesidewall thereof. Therefore, the sidewall 58 of the ring 56 is providedwith a concave configuration and a radially projecting portion 60extending about the entire periphery of the ring and the end of thetubular member 44 adjacent the cutting wheel 52 is provided with aradial projection 60 a. A similar radially projecting portion 62 islocated adjacent the opposite end of the ring 56, the radial projection62 being formed by a prior cutting stroke of the cutting tool.

In the drawings the amount of concavity and the height of the projectingportions 60 and 62 is greatly exaggerated for purposes of illustration.When the rings are cut from annealed stock the projections are not veryhigh and they are somewhat rounded. When the rings are cut from harderstock they tend to have a shape more closely approaching the illustratedshape. In both cases, however, the rings have zones at 60 and 62 whichare harder because of work-hardening. The radial projections so formedare useful in sealing and interlocking the sealing ring in the recessprovided by the body of a pipe union, as set forth in detail below.

As shown in phantom outline, the sealing ring 56 has a symmetricalconfiguration after it has been completely severed from the tubularmember. In particular, the sealing ring includes conical or radiallyextending end walls 64 and 66 which are inwardly flared as a result ofthe cutting operation. The end walls 64 and 66 radially extend from theprojecting portions 60 and 62, respectively, to the axially extendingbore 45.

Referring to FIG. 3, the pipe union 68 having a body 70 identical tothat illustrated in FIG. 1 is there shown. The body 70 has an enlargedhead portion 72 and an axially extending bore 74. Adjacent the enlargedhead portion 72 an annular recess 76 is provided about the bore 74. Therecess 76 provides a conical, radially extending end wall 78 and acylindrical sidewall 80. The body 70 includes an annular end face 82adjacent the head portion 72.

The completely severed sealing ring 56 is shown insened within therecess-76. As illustrated, the conical end wall 78 of the recess isshaped so as to mate with the end wall 64 of the ring 56. The ring 56fits with clearance into the recess 76 and the axial bore 74 of the bodyis aligned with the axial bore 45 of the ring. In the illustratedembodiment shown in FIG. 3, the radially projecting portions 62 and 60are adjacent the side wall of the recess.

Referring to FIG. 4, an intermediate stage in the forging stroke isillustrated. As shown, a forging tool 84 having a forward cylindricalportion 86 and a rearward conical portion 88 is employed to forge thering into the recess. The cylindrical portion 86 has a diametersubstantially equal to the diameter of the bores 45 and 74. Thus, thecylindrical portion 86 of the forging tool is initially introducedcoaxially into the bores without upsetting the ring so as to assureproper alignment and seating of the ring. However, as the forging strokecontinues, the conical shoulder 90 of the forging tool commences todeform the ring.

The work-hardened, radially projecting portions or zones 60 and 62provide the initial contact with the sidewall 80 of the recess, and asthe forging processes they are pressed with increased pressure againstthe sidewall 80 of the recesses. This tends to cause embedding of theedges 60 and 62 to occur even though the material of the body is harderthan the general hardness of the seal because of the localized hardnessof the edges at 60 and 62 and because of the high localized pressure. Asshown in FIGS. 4 and 5, the portions 60 and 62 of the sealing ring areembedded in the sidewall 80 of the recess as the ring is forged inplace. Here again, the amount of embedding is exaggerated for purposesof illustration. In contrast to prior art sealing rings, which aremerely tightly pressed against the adjacent walls of the body, portionsof the sealing ring of the work-hardened zones engage the walls of therecess with high localized pressure and thereby provide two spacedsealing zones.

Referring to FIG. 5, the forging tool 84 is illustrated at the end ofits forging stroke. The sealing ring 56 has been deformed to intimatelycontact the sidewalls 58 and 80 and the end walls 64 and 78 of the ringand the recess. In addition, the radially projecting portions 60 and 62of the sealing ring have been effectively embedded in the sidewall 80 ofthe recess so as to provide a sealing and interlocking structureidentical to that described with respect to the sealing ring 32illustrated in FIG. 1.

As the ring 56 is forged in place, the ring and portions of the enlargedhead 72 of the body 70 adjacent to the ring are radially expanded. Sincethe ferrous metal of the body 70 has more spring-back than the brassofthe seal, the body maintains a compressive stress on the ring andsecurely looks it in place, insuring a tight seal.

The forging operation provides the sealing and interlocking portions 60and 62 with greater radii than the adjacent portions of the body 70.Therefore, the seal is mechanically locked in place. It is not necessarythat both of the radial projections lie adjacent to the sidewall, sinceone of the radial projections will provide effective sealing andinterlocking when the ring is forged into place.

As shown in FIGS. 4 and 5, the conical shoulder 90 of the forging tool84 deforms the sealing ring 56 about the bore 45 to provide a conicalsurface 92. In some instances, further machining is performed to finishthe sealing surface 92 and the end wall 66. However, this does not haveto be done since the surface 66 is substantially coplanar with the endface 82 of the body and the surface 92 is sufficiently smooth tofunction as the seal.

Although a preferred embodiment of this invention is illustrated, it isto be understood that various modifications and rearrangements may beresorted to without departing from the scope of the invention disclosed.

What is claimed is:

l. A method of forming a pipe union or the like, including a body havingan axially extending bore therethrough and a work-hardening metal ringinsert positioned within a recess having a cylindrical sidewall and aradially extending end wall adjacent one end of said bore comprisingforming a ring proportioned to fit into said recess provided with asubstantially smooth annular work-hardened zone extending completelytherearound, forging said ring with a tool having a conical shoulder,and radially deforming said ring by axially moving said tool againstsaid ring causing said zone to uniformly engage said sidewall with amaximum pressure extending uniformly therearound to provide aninterlocking and-sealing connection between said ring and said bodywhich extends completely around said ring and producing a conicalsurface adjacent to one end face of said ring.

2. A method as set forth in claim 1, wherein said work-hardened zone isformed by deforming the material of said ring causing said zone toproject radially of said ring.

3. A method of forming a pipe union or the like as set 0 h in claim 2,wher in the ste of formin said rin inc udes cutting a tubular meriiberby a vanclng 2% cutting wheel radially in against said member from theoutside surface to simultaneously separate said ring from said memberand axially deform the material of said ring and produce said projectionat said outer surface.

4. A method of forming a pipe union or the like as set forth in claim 3,wherein the rings are sequentially cut from said tubular member andprojections are formed adjacent to each end.

1. A method of forming a pipe union or the like, including a body havingan axially extending bore therethrough and a workhardening metal ringinsert positioned within a recess having a cylindrical sidewall and aradially extending end wall adjacent one end of said bore comprisingforming a ring proportioned to fit into said recess provided with asubstantially smooth annular work-hardened zone extending completelytherearound, forging said ring with a tool having a conical shoulder,and radially deforming said ring by axially moving said tool againstsaid ring causing said zone to uniformly engage said sidewall with amaximum pressure extending uniformly therearound to provide aninterlocking and sealing connection between said ring and said bodywhich extends completely around said ring and producing a conicalsurface adjacent to one end face of said ring.
 2. A method as set forthin claim 1, wherein said work-hardened zone is formed by deforming thematerial of said ring causing said zone to project radially of saidring.
 3. A method of forming a pipe union or the like as set forth inclaim 2, wherein the step of forming said ring includes cutting atubular member by advancing a cutting wheel radially in against saidmember from the outside surface to simultaneously separate said ringfrom said member and axially deform the material of said ring andproduce said projection at said outer surface.
 4. A method of forming apipe union or the like as set forth in claim 3, wherein the rings aresequentially cut from said tubular member and projections are formedadjacent to each end.